About the stability of a D4-D̄4 system

Abstract

We study a system of coincident D4- and D̄4-branes with non-zero world-volume magnetic fields in the weak coupling limit. We show that the conditions for absence of tachyons in the spectrum coincide exactly with those found in [hep-th/0206041], in the low energy effective theory approach, for the system to preserve a 1 4 of the supersymmetries of the type IIA string theory vacuum. We present further evidence about the stability of the system by computing the lowest order interaction amplitude from both open and closed channels, thus verifying the no force condition as well as the supersymmetric character of the spectrum. A brief discussion of the low energy effective five-dimensional world-volume theory is given. © 2004 Elsevier B.V. All rights reserved.